This invention relates generally to turbines, and more particularly to hybrid turbines employing both impulse and reaction stages.
The single pressure Euler turbine was invented in 1754 by Euler. The original application for the turbine was as a water wheel. The turbine converts incoming kinetic energy in a fluid stream to shaft power through an internal compression and re-acceleration process.
Since 1754, other turbines have been invented and improved in many ways, all in an effort to improve efficiency. There is need to provide turbines having yet higher efficiencies with low cost, and for this purpose, hybrid turbines have been developed, employing both impulse and reaction stages. However, there remains need to develop hybrid turbines having yet higher efficiencies and lower costs.
It is a major object of the invention to provide an improved hybrid turbine having very high efficiency and/or low cost resulting from a simple structure.
It is another object of the invention to provide a hybrid turbine that achieves very high efficiency, by utilization and development of a fluid compression stage between impulse and reaction turbine stages.
Another object is to provide a turbine including a rotor on a shaft, and having:
a) stationary nozzles discharging fluid, thereby producing impulse forces on the rotor,
b) internal passages in the rotor producing compression of the fluid,
c) nozzles on the rotor discharging fluid to a pressure lower than the discharge pressure of the stationary nozzles, thereby producing reaction forces on the rotor,
d) whereby shaft power is produced. As will be seen, the turbine may utilize liquid or gas as a working fluid.
A further object is to provide a seal, or seals, or sealing means, located to enable the discharge pressure from the rotating nozzles to be lower than the discharge pressure from the stationary nozzles.
Yet another object is to provide radial vanes to cause fluid to rotate at the same velocity as the rotor; and in addition, all flow is preferably in generally radial directions, whereby there is substantially no resultant axial force on the rotor.
Another object is to provide a smooth, cylindrical plate to receive the flow from the stationary nozzles, shielding the rotor vanes from periodic forces.
An additional object is to provide a fluid driven turbine comprising, in combination:
a) first rotating fluid driven vanes defining an impulse turbine stage,
b) second rotating fluid driven vanes defining a reaction turbine stage,
c) and a fluid compression zone in the fluid path between the first and second vanes, and defining a fluid compression stage. As will be seen, the first vanes typically extend in a first ring, the second vanes extend in a second ring, the rings being coaxial, and the fluid compression zone is annular and located in the fluid path between the rings.
Another object is to provide a rotating surface toward which fluid travels and produces fluid compression. That surface may extend annularly and in coaxial relation with the vanes. In this regard, the first ring of vanes typically is stationary, and the second ring of vanes is rotating, there being structure carrying the second ring of vanes for rotation.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: